A novel tubular oxygen-permeable membrane reactor for partial oxidation of CH4 in coke oven gas to syngas

Abstract

Dense BaCo0.7Fe0.2Nb0.1O3−δ (BCFNO) membrane tubes were prepared by slip casting and readily brazed to 310S stainless steel supports using a silver-based alloy. A novel tubular membrane reactor was constructed by placing a cylindrical Ni-based monolithic catalyst coaxially around the tubular membrane and a conventional Ni-based catalyst-bed apart from the membrane tube. The novel membrane reactor was successfully applied to partial oxidation of CH4 in coke oven gas (COG). At 850 °C, 94% of CH4 conversion, 93% of H2 and as high as 11.3 cm3 cm−2 min−1 of oxygen permeation flux were obtained. The experimental H2 and CO selectivity and CH4 conversion were close to the thermodynamically predicated ones. There was a good match in the coefficient of thermal expansion (CTE) among BCFNO membrane, Ag-based alloy and 310S metal support. Long-term operation test results indicate that the novel tubular BCFNO membrane reactor exhibited not only high activity but also good stability for the partial oxidation of CH4 in COG to syngas.